- Jan 1 1st US public bath opens in New York City
- Jan 1 National debt of Britain & Ireland is 765,126,582 pounds
- Jan 1 Netherlands begins issuing postage stamps
- Jan 3 1st Chinese arrive in Hawaii
- Jan 17 British recognize independence of Transvaal (in South Africa)
- Feb 2 1st British public men's toilet opens in Fleet St, London
- Feb 2 Alexandre Dumas Jr's "La Dame aux Camélias" premieres in Paris
- Feb 11 First British public female toilet opens (Bedford Street, London)
- Feb 15 Great Ormond St Hospital for Sick Children, London, admits 1st patient
- Feb 16 Studebaker Brothers wagon company established - precursor of the automobile manufacturer
- Feb 19 The Phi Kappa Psi fraternity is founded at Jefferson College in Canonsburg, Pennsylvania
American Geographical Society
Feb 21 George Bancroft becomes the American Geographical Society's first president
- Feb 26 British troopship Birkenhead sinks off South Africa, 458 die, 193 survive
- Mar 1 Archibald William Montgomerie, 13th Earl of Eglinton appointed Lord Lieutenant of Ireland.
- Mar 3 14th Grand National: Alec Goodman wins first of 2 GN victories (1866) aboard Miss Mowbray
- Mar 7 Dutch telegraph traffic regulated by law
- Mar 13 Uncle Sam cartoon figure made its debut in the New York Lantern weekly
War Breaks Out Behind Uncle Tom's Cabin
Mar 20 Harriet Beecher Stowe's "Uncle Tom's Cabin" published in Boston
Music Premiere
Apr 30 Anton Rubinstein's opera "Dmitri Donskoi" premieres in St Petersburg, Russia
Deutsches Wörterbuch
May 1 Jacob and Wilhelm Grimm publish the first part of their German Dictionary "Deutsches Wörterbuch" (fully completed 1961)
- May 1 The Philippine peso is introduced into circulation
- May 8 Second London protocol signed reaffirming Danish federation control of independent Duchies of Holstein, Lauenburg and Schleswig
- May 18 Massachusetts rules all school-age children must attend school
- Jul 3 Congress authorizes US's 2nd mint (San Francisco, California)
What to the Slave is the Fourth of July?
Jul 5 Frederick Douglass, fugitive slave, delivers his 'What to the Slave Is the Fourth of July?' speech to the Ladies' Anti-Slavery Society in Rochester, condemns the celebration as hypocritical sham
- Jul 9 Fire destroys 1,100 construction sites in Montreal, Canada
- Jul 23 Private John Brown becomes the 1st interment in the National Cemetery at the Presidio in San Francisco, California
- Jul 31 Hottest July in Netherlands since at least 1783 (68.4°F (20.2°C) avg)
- Aug 1 San Francisco Methodists establish 1st black church, Zion Methodist
- Aug 3 America's first intercollegiate sporting event takes place as the Harvard heavyweight rowing crew beats Yale by 2 lengths over 2 miles on Lake Winnipesaukee, New Hampshire
- Aug 13 Steamer "Atlantic" crossing Lake Erie from Buffalo to Detroit collides with a fishing boat, sinks with 250 aboard
- Aug 21 Tlingit Indians destroy Fort Selkirk, Yukon Territory.
- Sep 3 Anti-Jewish riots break out in Stockholm, Sweden
- Sep 11 Olympia Columbian is 1st newspaper published north of Columbia River
- Sep 14 Samuel D Hubbard of Conn takes office as 18th US Postmaster General
- Sep 24 Henri Giffard, a French engineer, makes 1st engine powered dirigible/airship flight with steam power
- Sep 27 George Aiken's play "Uncle Tom's Cabin" an adaptation of Harriet Beecher Stowe's famous anti-slavery novel premieres in Troy, New York
Historic Expedition
Oct 1 Alfred Russel Wallace returns to the U.K. after four years of travel, collecting, and research in South America
Election of Interest
Nov 2 Franklin Pierce elected as President of US
- Nov 4 Count Camillo Benso di Cavour becomes the prime minister of Piedmont-Sardinia, which soon expands to become Italy
- Nov 18 Rose Philippine Duchesne dies in St. Charles, Missouri. She would be canonized on July 3, 1988 by Pope John Paul II.
- Nov 18 State funeral of Duke of Wellington (St Paul's Cathedral, London)
- Nov 20 Charles Reade and Tom Taylor's historical comedy play "Masks & Faces" premieres in London
- Nov 21 Duke University founded in 1838 as Union Institute, chartered as Normal College
- Nov 23 Just past midnight, a sharp jolt likely caused by heavy rains causes Lake Merced, California, to drop 30 feet (9m)
- Dec 1 Telegraph company opens throughout Netherlands
- Dec 8 Gustav Freytag's comedy play "The Journalists" premieres in Breslau
- Dec 17 1st Hawaiian cavalry organized
Election of Interest
Dec 18 George Hamilton-Gordon (Peelite party) becomes Prime Minister of the United Kingdom after the downfall of the Conservative government of Edward Smith-Stanley